// Framework grid generation
//
// Used only by Bootstrap to generate the correct number of grid classes given
// any value of `@grid-columns`.

.make-grid-columns() {
    // Common styles for all sizes of grid columns, widths 1-12
    .col(@index) { // initial
      @item: ~".col-xs-@{index}, .col-sm-@{index}, .col-md-@{index}, .col-lg-@{index}";
      .col((@index + 1), @item);
    }
    .col(@index, @list) when (@index =< @grid-columns) { // general; "=<" isn't a typo
      @item: ~".col-xs-@{index}, .col-sm-@{index}, .col-md-@{index}, .col-lg-@{index}";
      .col((@index + 1), ~"@{list}, @{item}");
    }
    .col(@index, @list) when (@index > @grid-columns) { // terminal
      @{list} {
        box-sizing: border-box;
        position: relative;
        // Prevent columns from collapsing when empty
        min-height: 1px;
        // Inner gutter via padding
        padding-right: floor((@grid-gutter-width / 2));
        padding-left: ceil((@grid-gutter-width / 2));
      }
    }
    .col(1); // kickstart it
  }
  
  .float-grid-columns(@class) {
    .col(@index) { // initial
      @item: ~".col-@{class}-@{index}";
      .col((@index + 1), @item);
    }
    .col(@index, @list) when (@index =< @grid-columns) { // general
      @item: ~".col-@{class}-@{index}";
      .col((@index + 1), ~"@{list}, @{item}");
    }
    .col(@index, @list) when (@index > @grid-columns) { // terminal
      @{list} {
        float: left;
      }
    }
    .col(1); // kickstart it
  }
  
  .calc-grid-column(@index, @class, @type) when (@type = width) and (@index > 0) {
    .col-@{class}-@{index} {
      width: percentage((@index / @grid-columns));
    }
  }
  .calc-grid-column(@index, @class, @type) when (@type = push) and (@index > 0) {
    .col-@{class}-push-@{index} {
      left: percentage((@index / @grid-columns));
    }
  }
  .calc-grid-column(@index, @class, @type) when (@type = push) and (@index = 0) {
    .col-@{class}-push-0 {
      left: auto;
    }
  }
  .calc-grid-column(@index, @class, @type) when (@type = pull) and (@index > 0) {
    .col-@{class}-pull-@{index} {
      right: percentage((@index / @grid-columns));
    }
  }
  .calc-grid-column(@index, @class, @type) when (@type = pull) and (@index = 0) {
    .col-@{class}-pull-0 {
      right: auto;
    }
  }
  .calc-grid-column(@index, @class, @type) when (@type = offset) {
    .col-@{class}-offset-@{index} {
      margin-left: percentage((@index / @grid-columns));
    }
  }
  
  // Basic looping in LESS
  .loop-grid-columns(@index, @class, @type) when (@index >= 0) {
    .calc-grid-column(@index, @class, @type);
    // next iteration
    .loop-grid-columns((@index - 1), @class, @type);
  }
  
  // Create grid for specific class
  .make-grid(@class) {
    .float-grid-columns(@class);
    .loop-grid-columns(@grid-columns, @class, width);
    .loop-grid-columns(@grid-columns, @class, pull);
    .loop-grid-columns(@grid-columns, @class, push);
    .loop-grid-columns(@grid-columns, @class, offset);
  }